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Old Yesterday, 09:18 AM
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Throttle pulsing in Cruise Mode

Well, with the nicer weather here I've finally been able to get the Skywalker out and do some range testing of the FrSky tx module and rx. 4k with still 45% RSSI! Impressive for a 2.4ghz system.

Anyway, while viewing footage from the onboard GoPro I noticed the throttle could be heard pulsing while flying level in Cruise Mode. Throttle was smooth while making alt changes, or while flying in any other flight mode.
A Google search revealed some old conversation on the subject, and possible solutions were to change THR_SLEWRATE values, or to flash ESC with SimonK firmware.
I haven't tryed anything yet, but I thought I'd post it here to see if any of you have seen this issue.

Thanks!

Fergy
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Old Yesterday, 10:25 AM
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Quote:
Originally Posted by pekote View Post
Finally I found the problem. During flight the compass was giving "Compass bad health" error. It seemed that somewhere in the wiring there is a problem (since I landed and the error disappeared). I've seen the error a couple of times during flight.

I checked the cables and everything worked fine since there, but I'm still afraid to get the error again since I didn't find nothing relevant.

I also checked that the compass didn't modify their angle at full throttle.

Now I know, how relevant is the compass for flight navigation.

I have to say that my bixler 3 performed perfect circles during LOITER or RTL modes. It works really nice!! I was really surprised about the precision, really happy for that!!
You can perfectly fly without compass, that's what happens when it shows bad compass health, or you can change a parameter to turn off the compass.

If I remember well, this happens when the gps heading and the compass are too different, it then only uses the gps heading.
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Old Yesterday, 12:16 PM
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Quote:
Originally Posted by flipflap View Post
You can perfectly fly without compass, that's what happens when it shows bad compass health, or you can change a parameter to turn off the compass.

If I remember well, this happens when the gps heading and the compass are too different, it then only uses the gps heading.
Hello, flipflap,

Is there any way to check the GPS compass heading??
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Old Yesterday, 03:07 PM
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Short and Long Failsafe and RTH

I was wondering why the APM comes with the default method of : Short Fail Safe (1.5s): Circle-> Long Fail Safe (20s): RTH

I was expecting to have only one action by default due to FS-> RTH as soon as possible.

Since I have no experience with APM, I'm just in my first steps, I just wanted to do an small survey and know what the the experienced pilots do with this FS settings.

Thanks for comments.

Regards from Argentina
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Old Yesterday, 03:23 PM
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Quote:
Originally Posted by pekote View Post
I was wondering why the APM comes with the default method of : Short Fail Safe (1.5s): Circle-> Long Fail Safe (20s): RTH

I was expecting to have only one action by default due to FS-> RTH as soon as possible.

Since I have no experience with APM, I'm just in my first steps, I just wanted to do an small survey and know what the the experienced pilots do with this FS settings.

Thanks for comments.

Regards from Argentina
I use FrSky tx/rx so ,instead of using the APM failsafe, I just set the failsafe on my radio to RTH. I can't think of a situation where the GCS failsafe would be more useful but perhaps others can enlighten us why it would be.

Cheers,
Geoff
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Old Yesterday, 04:04 PM
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I was referring to the short fail safe and long fail safe.

I also have frsky setup as you Geoff, and also configured to go to RTH, but did you noticed that the APM default setup has two FS settings, short and long?


http://plane.ardupilot.com/wiki/ardu...efs_short_actn

Failsafe Parameters and their meanings

Short failsafe action (Plane:FS_SHORT_ACTN)

The action to take on a short (1.5 seconds) failsafe event in AUTO, GUIDED or LOITER modes. A short failsafe event in stabilization modes will always cause a change to CIRCLE mode. In AUTO mode you can choose whether it will RTL (ReturnToLaunch) or continue with the mission. If FS_SHORT_ACTN is 0 then it will continue with the mission, if it is 1 then it will enter CIRCLE mode, and then enter RTL if the failsafe condition persists for 20 seconds.

VALUE MEANING
0 Continue
1 Circle/ReturnToLaunch
Long failsafe action (Plane:FS_LONG_ACTN)

The action to take on a long (20 second) failsafe event in AUTO, GUIDED or LOITER modes. A long failsafe event in stabilization modes will always cause an RTL (ReturnToLaunch). In AUTO modes you can choose whether it will RTL or continue with the mission. If FS_LONG_ACTN is 0 then it will continue with the mission, if it is 1 then it will enter RTL mode. Note that if FS_SHORT_ACTN is 1, then the aircraft will enter CIRCLE mode after 1.5 seconds of failsafe, and will always enter RTL after 20 seconds of failsafe, regardless of the FS_LONG_ACTN setting.

VALUE MEANING
0 Continue
1 ReturnToLaunch
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Old Yesterday, 07:08 PM
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Quote:
Originally Posted by pekote View Post
I was wondering why the APM comes with the default method of : Short Fail Safe (1.5s): Circle-> Long Fail Safe (20s): RTH



I was expecting to have only one action by default due to FS-> RTH as soon as possible.



Since I have no experience with APM, I'm just in my first steps, I just wanted to do an small survey and know what the the experienced pilots do with this FS settings.



Thanks for comments.



Regards from Argentina

It gives a little time to reacquire the signal before activating RTL. Once RTL is activated (Long FS) it won't change modes even when the signal is restored. You have to override RTL by manually switching modes. If you have a brief signal loss that causes a Short FS it will enter a very gentle circle until either signal is restored or Short FS expires.
I think it works great at the stock settings. It prevents any spurious abrupt maneuvers. Using the Rx FS can cause erratic behavior when the signal it intermittent. I almost lost a plane this way once (different autopilot). Also, if your connection between the Rx and APM is broken, the Rx FS won't work.
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Old Yesterday, 10:40 PM
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If you use the FRSKY receiver FS the FC doesn't know that a FS situation is in play, just knows that it has been commanded to RTL. You still have to make sure that the FC knows what to do in the event that it cannot RTL (no GPS/glitch). I seem to recall that there were situations where the flight mode change request to RTL is ignored if it cannot be acted on and the existing FM retained, is this still the case?
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Old Today, 12:16 AM
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Quote:
Originally Posted by GFergy View Post
... I noticed the throttle could be heard pulsing while flying level in Cruise Mode. Throttle was smooth while making alt changes, or while flying in any other flight mode
Yes, the throttle is pulsing due to a high THR slew rate. Try decreasing it, 30-40%, you'll notice a change.
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Old Today, 03:08 AM
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Hi guys im pulling my hair with this mavlink-osd v2.0 and the APM 2.6 running latest plane FW.

Everything is working fine APM and all except i get an error on OSD "no mav link", APM is configured following this settings:

https://code.google.com/p/minimosd-extra/wiki/APM

On mavlink OSD im running latest Fw and chartset from minimosd-extra...


I have no clue what more to do to get osd working...

APM 2.6, mavlink-osd v 2.0, using Y cable with 433Mhz telemetry. Telemetry and osd connected with ground, VCC and RX.

If anyone has a clue what is the problem i would be really grateful... coz im ready to throw it in the bin after spending 5-6h yesterday and i couldnt get it to work properly.

Thanks
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Old Today, 03:11 AM
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Quote:
Originally Posted by gbmarsh View Post
In a nutshell, yes Using heading data from the compass and position data and ground speed from the GPS, the APM does a pretty good job of estimating wind speed and direction. It surprised me when I first noticed it too, I think they use voodoo

Cheers,
Geoff
That is some pretty sweet voodoo they've got going on there then!
I assume that there is still some advantage of having an pitot then?
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Old Today, 03:25 AM
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Use of airspeed sensor and pitot tube is said to result in a more precise airspeed reading for ardupilot.
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Old Today, 03:40 AM
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Quote:
Originally Posted by pekote View Post
Hello, flipflap,

Is there any way to check the GPS compass heading??
You mean the compass which is integrated in the gps box ? I think it's visible in the status screen, you know the list will all the telemetry values in small print. maybe around mag or magnetometer. (I don't have mission planner at work and can't check exactly the naming).

At least the raw xyz values are available, I'm not certain the calculated heading is shown too.
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